FIG. 6 is an exploded perspective view of a multifunctional switch of the prior art, FIG. 7 an exterior view of the same switch, FIG. 8 a sectional view of the same switch, and FIG. 9 a plan view of a switch casing.
A push switch is provided inside circular wall 1A of switch casing 1 (refer to FIGS. 8 and 9). The push switch comprises contacts 2A and 2B, dome-like movable contact 6 made of a sheet metal, and push button 7. A peripheral rim of dome-like contact 6 is in contact with contact 2B. Contacts 2A and 2B are connected with terminals 4A and 4B respectively.
When push button 7 is pressed, the dome-like shape of movable contact 6 deforms elastically to come into contact with contact 2A, thereby making a continuity between terminals 4A and 4B. When the pressing force is removed from push button 7, movable contact 6 recovers its original dome-like shape by its elasticity, and breaks the continuity between terminals 4A and 4B.
A rotary switch is provided outside of circular wall 1A (refer to FIGS. 8 and 9). The rotary switch comprises contacts 3A, 3B and 3C, rotatable body 9, sliding contact 10 (refer to FIGS. 6 and 8), and spring 8. Contacts 3A, 3B and 3C are connected with terminals 5A, 5B and 5C respectively.
Rotatable body 9 having sliding contact 10 mounted to the underside thereof is engaged to circular wall 1A in a freely rotatable manner. A pair of bosses 9C provided on the underside of rotatable body 9 catch both ends of spring 8, which is disposed to protrusion 1B of switch casing 1 (refer to FIG. 9).
When a turning force is applied clockwise to rotatable body 9, boss 9C shown on the left side of FIG. 9 shifts upward while bending one end of spring 8 as illustrated by the dotted line. The other end of spring 8 is caught immovable by one of stoppers 1C on the right side. In this state, sliding contact 10 is in a position that contact shoes 10A and 10B are in contact with their respective contacts 3A and 3B, thereby making a continuity between terminals 5A and 5B.
When the turning force is removed, rotatable body 9 returns to its original angular position, or the neutral state, by the elasticity of spring 8. When rotatable body 9 comes into this state, the continuity is cut between terminals 5A and 5B because both contact shoes 10A and 10B of sliding contact 10 are on the surface of contact 3A.
When a turning force is applied counterclockwise to rotatable body 9, boss 9C shown on the right side shifts upward, and this makes a continuity between terminals 5A and 5C. When the turning force is removed, rotatable body 9 returns to the neutral state to break the continuity between terminals 5A and 5C in the same manner as described above.
In the multifunctional switch of the prior art described above, an operating knob, not shown, is attached to projections 9D on the upper side of rotatable body 9 to operate the rotary switch. In other words, operating means are located on the upper surface for both the push switch and the rotary switch. For use in the latest electronic apparatuses, however, there is a demand for multifunctional switches of a type having a combination of a vertically operable push switch and a laterally operable rotary switch.
Japanese Utility Model Unexamined Publication, No. 1991-82535 is one example of the known prior art documents related to conventional multifunctional switches of the type discussed above.